QAYYARAH, IRAQ - OCTOBER 21: A boy pauses on his bike as he passes an oil field that was set on fire by retreating ISIS fighters ahead of the Mosul offensive, on October 21, 2016 in Qayyarah, Iraq. Several hundred Iraqi families have been made to leave their homes for Mosul by Islamic State fighters as the UN warns they could be used as human shields. ISIS have attacked Kirkuk today as Kurdish and Iraqi forces, backed by a coalition including Britain and the U.S.A continue their offensive to retake Iraq's second largest city of Mosul. (Photo by Carl Court/Getty Images)